JP2016137630A - Reciprocation work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reciprocation work machine of a simple structure capable of changing a stroke quantity of reciprocatably operating a tool support member.SOLUTION: A jigsaw 10 comprises a motion conversion mechanism 96 for reciprocating a plunger 42 in the direction along the axis C1 by torque of a rotary member 26, and comprises an operation control mechanism 58 for switching to the orbital control nonexistence for operating the plunger 42 only in the direction along the axis C1 and the orbital control existence for operating the plunger 42 in an elliptical shape, an electric motor 17 for switching the rotational direction of the rotary member 26 to normal rotation and reverse rotation, and a stroke quantity changing mechanism 88 for making a stroke quantity of reciprocating the plunger 42 different when the rotary member 26 normally rotates and when reversely rotating.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a reciprocating machine that reciprocates a work tool with the power of a motor.

  2. Description of the Related Art Conventionally, a reciprocating machine that processes a target object by reciprocating a work tool with the power of a motor is known. The reciprocating machine described in Patent Document 1 includes an armature pinion of a motor, a gear that is rotatably provided in the main body and meshes with the armature pinion, a cam housing portion that is provided eccentrically from the rotation center of the gear, And a cylindrical cam disposed in the cam housing portion. Further, an elastic member for positioning the gear in the center line direction is provided. The cam is rotatable in the cam housing and is fixed at a predetermined position. A positioning mechanism is provided between the cam and the cam housing portion. The rotation center of the cam is eccentric from the rotation center of the gear. A pin is attached at a position eccentric from the rotation center of the cam.

  Furthermore, a plunger arranged to be movable in the length direction in the main body, a connector attached to the plunger, and a cutting blade as a work tool supported by the connector are provided. The connector has two plates parallel to each other, and the needle bearing attached to the pin is movable between the two plates.

  In the reciprocating machine described in Patent Literature 1, when the armature pinion of the motor rotates, the rotational force is transmitted to the gear and the gear rotates. Then, the pin provided in the cam revolves around the rotation center of the gear. Further, the needle bearing moves between the two plates, the revolving force of the pin is converted into the reciprocating force of the plunger, and the object is cut by the cutting blade.

  When changing the stroke amount that the plunger reciprocates, the motor is stopped and the gear is moved in the direction along the rotation center line against the force of the elastic member to release the positioning mechanism. Next, the cam is rotated 180 degrees. Then, the radius from the rotation center of the gear to the center of the pin is changed. Further, the gear is moved in the rotation center line direction to return to the original position, and the cam is positioned in the rotation direction by the positioning mechanism.

JP 2000-225517 A

  However, the reciprocating machine described in Patent Document 1 must be provided with a cam accommodating portion and a positioning mechanism in the gear, and an elastic member that prevents the gear from moving in the center line direction. It was complicated.

  An object of the present invention is to provide a reciprocating machine with a simple structure that can change the stroke amount that the tool support member reciprocates.

  The reciprocating machine according to an embodiment is a reciprocating machine having a motion conversion mechanism that reciprocates the tool support member in the first direction by the rotational force of the rotating member, wherein the tool support member is the first support device. An operation control mechanism that switches between a first operation state that operates only in a direction and a second operation state that operates in a second direction that intersects the first direction in addition to the first direction; and the rotating member A rotation direction switching mechanism that switches the rotation direction between forward rotation and reverse rotation, and a stroke amount change that makes the stroke amount that the tool support member reciprocates differ between when the rotation member rotates forward and when it rotates backward And a mechanism.

  According to the present invention, the stroke amount that the tool support member reciprocates with a simple structure can be changed.

It is a front sectional view of a jigsaw to which the reciprocating machine according to the present invention is applied. It is a fragmentary sectional view of the jigsaw shown in FIG. (A)-(D) are the partial side views of the jigsaw shown in FIG. It is a partial front sectional view of the jigsaw shown in FIG. It is a partial side view of the jigsaw shown in FIG. (A)-(C) are the partial back views of the jigsaw shown in FIG. It is a partial side view of the jigsaw shown in FIG. It is a block diagram which shows the control system of the jigsaw shown in FIG. (A)-(D) are the partial side views of the jigsaw shown in FIG. (A), (B) is a fragmentary sectional view of the jigsaw shown in FIG. (A), (B) is a figure which shows the other example of a stroke amount control mechanism. It is front sectional drawing of the stroke amount control mechanism shown in FIG. It is a flowchart which shows the control which can be performed by the motor control part shown in FIG. It is a block diagram which shows the other example of the control system of the jigsaw shown in FIG. It is a flowchart which shows the other control which can be performed with the motor control part shown in FIG.

  An embodiment in which a reciprocating machine according to the present invention is applied to a jigsaw will be described with reference to the drawings.

  The object 11 to be cut by the jigsaw 10 shown in FIGS. 1 and 2 includes wood, mild steel plate, and stainless steel. The jigsaw 10 includes a housing 12. The housing 12 includes a motor case 13, a gear case 14 fixed to the motor case 13, a handle 15 that connects the motor case 13 and the gear case 14, and an opening of the gear case 14. And a cover 16 for covering. A housing chamber A1 is formed by the gear case 14 and the cover 16.

  An electric motor 17 is provided in the motor case 13. The electric motor 17 has a stator 18 as an armature and a rotor 19 as a field. The stator 18 is provided so as not to rotate in the motor case 13, and the rotor 19 is provided so as to be rotatable in the motor case 13. The stator 18 includes three coils V1, U1, and W1 wound around a stator core. The rotor 19 includes a rotor core 21 fixed to the output shaft 20 and four permanent magnets 22 attached to the rotor core 21 at intervals in the rotational direction. The output shaft 20 is disposed from the motor case 13 to the accommodation chamber A1. The gear case 14 is provided with a bearing 23 that rotatably supports the output shaft 20. A fan 24 is attached to the output shaft 20, and the fan 24 rotates together with the output shaft 20 to form an air flow and suppresses an increase in temperature of the electric motor 17.

  A pinion gear 28 is formed at a position of the output shaft 20 disposed in the storage chamber A1. A support shaft 25 parallel to the output shaft 20 is fixed to the gear case 14, and a rotating member 26 is attached to the support shaft 25. The rotating member 26 is supported by the support shaft 25 so as to be rotatable about the axis B1. A gear 27 is formed on the outer periphery of the rotating member 26, and the gear 27 meshes with the pinion gear 28.

  The rotating member 26 includes an eccentric shaft 29. The eccentric shaft 29 protrudes from the end surface of the rotating member 26 in a direction along the axis B1. The outer peripheral shape of the eccentric shaft 29 is circular, and the center of the eccentric shaft 29 is eccentric in the radial direction from the axis B1. A balance weight 30 is attached to the eccentric shaft 29. The balance weight 30 is integrally formed of metal. The balance weight 30 is provided with a long hole 31 penetrating in a direction along the axis B <b> 1, and the eccentric shaft 29 is disposed in the long hole 31. The balance weight 30 can reciprocate in the direction perpendicular to the axis B1 in the accommodating chamber A1, that is, in the vertical direction in FIG.

  Furthermore, a concave portion 32 is provided on the opposite side of the end surface of the rotating member 26 from the location where the eccentric shaft 29 is provided. The recess 32 has a depth in the direction along the axis B1, and has a substantially circular inner peripheral surface 33 with the axis B1 as the center, as shown in FIG. An end portion of the support shaft 25 is disposed in the recess 32. Further, two stoppers 34 and 35 projecting inward in the radial direction from the inner peripheral surface 33 are provided. The two stoppers 34 and 35 are arranged in different ranges in the rotating direction of the rotating member 26. In the rotational direction of the rotating member 26, the center of the stopper 34 and the center of the stopper 35 are at different positions within a range of 140 degrees to 150 degrees.

  Further, as shown in FIGS. 3 and 4, a plate 37 that can be operated with the support shaft 36 as a fulcrum is attached to the rotating member 26. The support shaft 36 is provided at a position eccentric from the support shaft 25 in the recess 32. The plate 37 is disposed in the recess 32, and a guide hole 38 that penetrates the plate 37 in the thickness direction is provided. The guide hole 38 is arranged in an arc shape around the support shaft 36. The support shaft 25 is disposed in the guide hole 38.

  Further, a support shaft 39 is fixed to the plate 37. The support shaft 39 is provided on the plate 37 on the side opposite to the support shaft 36. The guide hole 38 is disposed between the support shaft 36 and the support shaft 39. A connecting piece 41 is attached to the support shaft 39 via a needle bearing 40. The connecting piece 41 is formed by integrally forming a steel material into a cylindrical shape.

  A plunger 42 is provided from the inside to the outside of the storage chamber A1. A saw blade 43 is attached to the end of the plunger 42 in the direction along the center line C <b> 1 via a fixture 49. The saw blade 43 is disposed outside the storage chamber A1. A large number of teeth are formed on the side edge of the saw blade 43 in the direction along the center line C1.

  As shown in FIGS. 2 and 5, the contact member 44 is provided on the plunger 42. The contact member 44 includes rails 45A and 45B that are parallel to each other, and connects the support shaft 39 and the plunger 42 so that power can be transmitted. 2 and 5, the rail 45A is disposed above the rail 45B in the direction of the center line C1. The two rails 45A and 45B extend in a direction orthogonal to the center line C1, and the connecting piece 41 rolls in a direction orthogonal to the center line C1 between the two rails 45A and 45B. Is possible.

  A support shaft 46 is provided on the cover 16, and a holder 47 is provided so as to be swingable with the support shaft 46 as a fulcrum. The holder 47 is disposed in the storage chamber A <b> 1 and supports the plunger 42 via two slide bearings 48. For this reason, the plunger 42 is movable in the direction along the center line C <b> 1 while being supported by the slide bearing 48. The support shaft 25 is disposed between the support shaft 46 and the output shaft 20 in the vertical direction in FIG. 2, that is, in the direction along the center line C <b> 1.

  Further, a compression spring 50 is provided that urges the plunger 42 and the saw blade 43 supported by the holder 47 with the support shaft 46 as a fulcrum. The plunger 42 and the saw blade 43 shown in FIG. 2 are urged clockwise around the support shaft 46 by the urging force of the compression spring 50.

  Further, a cam plate 51 is attached to the eccentric shaft 29. The cam plate 51 is disposed between the rotating member 26 and the balance weight 30. A long hole 52 is provided in the cam plate 51, and the eccentric shaft 29 is movably disposed in the long hole 52. The cam plate 51 is provided with a linear slit 53 extending in the vertical direction in FIG. A part of the output shaft 20 is disposed in the slit 53. When the rotating member 26 rotates, the cam plate 51 can move in the vertical direction in FIG. 2 with the output shaft 20 disposed in the slit 53.

  A contact 54 is attached to the gear case 14. The contact 54 is movable in the vertical direction in FIG. The end of the cam plate 51 contacts the contact 54.

  Further, a swing arm 55 is attached to the cover 16. The swing arm 55 can swing within a predetermined angle range about the support shaft 56 clockwise and counterclockwise in FIG. A roller 57 is rotatably attached to one end of the swing arm 55. The saw blade 43 biased by the compression spring 50 contacts the roller 57, and the swing arm 55 is biased clockwise with the support shaft 56 as a fulcrum in FIG.

  Further, as shown in FIG. 6, a switching lever 59 is provided outside the gear case 14. The restriction shaft 60 is fixed to the switching lever 59, and when the operator operates the switching lever 59, the switching lever 59 rotates together with the restriction shaft 60. The switching lever 59 can rotate within a predetermined angle range around the restriction shaft 60. Three operation positions D1 to D3 of the switching lever 59 are shown on the outer surface of the gear case 14. The restriction shaft 60 includes a notch 61 and a stopper 62.

  An operation control mechanism 58 is configured by the cam plate 51, the contact 54, the swing arm 55, the roller 57, the compression spring 50, and the restriction shaft 60. The operation control mechanism 58 is also called an orbital mechanism, and is a mechanism that switches the operation trajectories of the plunger 42 and the saw blade 43 in the front view of the jigsaw 10 in FIGS. 1 and 2.

  As shown in FIG. 7, the switching lever 59 is provided with a storage portion 64, and the compression spring 65 and the ball 66 are stored in the storage portion 64. Recesses 67 corresponding to the operation positions D1 to D3 are provided on the outer surface of the gear case 14, respectively. When the ball 66 pushed by the compression spring 65 enters the recess 67, the operator can recognize by feeling that the switching lever 59 is located at any one of the operation positions D1 to D3.

  When the tactile switch 68 is attached to the inner surface of the gear case 14, the switching lever 59 is stopped at the operation position D3, and the ball 66 enters the recess 67, the tactile switch 68 is turned on. When the switching lever 59 is at the operation position D1 or the operation position D2, the tactile switch 68 is turned off.

  Furthermore, a base 63 is attached to the gear case 14. As shown in FIG. 1, the handle 15 is provided with a trigger 69. A trigger switch 71 is provided in the handle 15. When the operator applies operating force to the trigger 69, the trigger switch 71 is turned on, and when the operating force applied to the trigger 69 is released, the trigger switch 71 is turned off. The handle 15 is provided with a rotation speed setting dial 72 for setting the rotation speed of the electric motor 17 by an operator. Further, a power cord 70 is connected to a connection portion between the handle 15 and the motor case 13.

  Next, a control system of the electric motor 17 will be described with reference to FIG. The housing 12 is provided with a display unit 73. The display unit 73 displays the set target rotational speed. The stator 18 of the electric motor 17 has three coils U1, V1, and W1 corresponding to the U phase, the V phase, and the W phase. As a sensor for detecting the rotational position of the rotor 19, three Hall elements H1 to H3 corresponding to the three-phase coils U1, V1, and W1 are provided. The three Hall elements H1 to H3 detect the strength of the magnetic field formed by the permanent magnet 22 provided on the rotor 19 and output a detection signal.

  In addition, an inverter circuit 74 is provided for controlling the drive current for the three coils U1, V1, and W1. Between the AC power supply 75 and the inverter circuit 74, a rectifier circuit 76 for rectifying the AC of the AC power supply 75 into a DC, and a power factor improving circuit for boosting the rectified DC voltage and supplying it to the inverter circuit 74 77 is interposed. The power factor correction circuit 77 has an integrated circuit 78 that outputs a control signal to the transistor 97. Note that a noise countermeasure circuit 79 is provided between the AC power supply 75 and the rectifier circuit 76 to prevent noise generated in the inverter circuit 74 from being transmitted to the AC power supply 75 side.

  The inverter circuit 74 is a three-phase full-bridge inverter circuit, and includes two switching elements Tr1, Tr2 connected in series, two switching elements Tr3, Tr4, and two switching elements Tr5, Tr6, Each of the switching elements Tr1 to Tr6 is connected to the positive and negative output terminals of the power factor correction circuit 77. The three switching elements Tr1, Tr3, Tr5 connected to the positive electrode side are on the high side, and the three switching elements Tr2, Tr4, Tr6 connected to the negative electrode side are on the low side. One connection terminal of the U-phase coil U1 is connected between the two switching elements Tr1 and Tr2. One connection terminal of the V-phase coil V1 is connected between the two switching elements Tr3 and Tr4. One connection terminal of the W-phase coil W1 is connected between the two switching elements Tr5 and Tr6. The other connection terminals of the three coils U1, V1, and W1 are connected to each other, and the coils U1, V1, and W1 are star-connected.

  For example, when a control signal is applied to the gates of the high-side switching element Tr1 and the low-side switching element Tr4, current is supplied to the U-phase and V-phase coils U1 and V1. By adjusting the timing of the control signal supplied to each switching element, the commutation operation for each coil U1, V1, W1 is controlled. Thus, the inverter circuit 74 has a rectifying function, and the electric motor 17 is not provided with a commutator on the output shaft 20 and does not have a brush for supplying current to the commutator. That is, the electric motor 17 is a brushless motor.

  A motor control unit 80 that controls the inverter circuit 74 is provided, and the motor control unit 80 includes a controller 81. A control signal is sent from the controller 81 to the inverter circuit 74 via the control signal output circuit 82. The detection signals of the Hall elements H1 to H3 are sent to the rotor position detection circuit 83. A signal output from the rotor position detection circuit 83 is sent to the controller 81 and the motor rotation number detection circuit 84. The motor rotation speed detection circuit 84 calculates the rotation speed of the output shaft 20 of the electric motor 17, that is, the actual rotation speed. A signal output from the motor rotation speed detection circuit 84 is sent to the controller 81. A motor current detection circuit 85 that detects a current flowing through the electric motor 17 is provided, and a signal output from the motor current detection circuit 85 is input to the controller 81. A trigger switch detection circuit 86 for detecting on / off of the trigger switch 71 is provided, and a signal output from the trigger switch detection circuit 86 is input to the controller 81.

  The controller 81 includes a microprocessor that calculates a control signal to be output to the control signal output circuit 82, and a memory that stores a program, an arithmetic expression, and data used to control the rotation speed of the electric motor 17. The controller 81 determines the rotation and stop of the electric motor 17, the rotation direction, and the rotation speed based on the tactile switch 68, the rotation speed setting dial 72, the signal input from the detection circuit, the stored program, arithmetic expression, and data. Control.

  The rotation speed of the electric motor 17 is controlled by adjusting the voltages supplied to the three coils U1, V1, and W1. The voltage control for the three coils U1, V1, and W1 is performed by PWM (Pulse Width Modulation) control of the switching elements Tr1 to Tr6. That is, it is performed by adjusting the duty ratio of the ON signal applied to the gates of the switching elements Tr1 to Tr6 of the inverter circuit 74. The rotation direction of the electric motor 17 is controlled by switching the direction of the current flowing through the three coils U1, V1, and W1. The inverter circuit 74, the rectifier circuit 76, the power factor correction circuit 77, and the motor control unit 80 are provided on the control board 87 shown in FIG. The control board 87 is provided in the motor case 13.

  Next, the operation of the jigsaw 10 will be described. After connecting the power cord 70 to the AC power source 75, the worker holds the handle 15 and presses the base 63 against the object 11. When an operating force is applied to the trigger 69, electric power is supplied to the electric motor 17, and the output shaft 20 rotates. The torque of the output shaft 20 is transmitted to the rotating member 26 via the pinion gear 28 and the gear 27, and the rotating member 26 rotates about the support shaft 25. Further, the plate 37 rotates together with the rotating member 26. The electric motor 17 can switch the rotation direction of the output shaft 20 between the first rotation direction and the second rotation direction. The rotation direction of the output shaft 20 of the electric motor 17 can be switched by operating the switching lever 59. The motor control unit 80 switches the rotation direction of the output shaft 20 of the electric motor 17 depending on whether the tactile switch 68 is turned on or off when the switching lever 59 is operated.

  When the switching lever 59 is at the operation position D1 or the operation position D2, the output shaft 20 rotates in the first rotation direction, and the rotation member 26 rotates clockwise as shown in FIG. The direction in which the rotating member 26 rotates clockwise in FIG. 3 is referred to as normal rotation. When the switching lever 59 is at the operation position D3, the output shaft 20 rotates in the second rotation direction, and the rotating member 26 rotates counterclockwise as shown in FIG. The direction in which the rotating member 26 rotates counterclockwise in FIG. 9 is referred to as reverse rotation.

  When the plate 37 rotates with the rotating member 26, the connecting piece 41 revolves around the support shaft 25 regardless of the rotating direction of the rotating member 26. Further, the connecting piece 41 reciprocates between the rails 45A and 45B as shown in FIG. In this way, the revolution force of the support shaft 39 is transmitted to the contact member 44 via the connecting piece 41, and the plunger 42 reciprocates in the direction along the center line C1, that is, rises and falls. Then, the saw blade 43 is raised and lowered together with the plunger 42, and the object 11 is cut. Thus, in the jigsaw 10, the rotational force of the output shaft 20 of the electric motor 17 is converted into the reciprocating power of the plunger 42 and the saw blade 43. The support shaft 39, the connecting piece 41, and the contact member 44 constitute a motion conversion mechanism 96.

  Next, when the switching lever 59 is at the operation position D1 as shown in FIG. 6A and the rotating member 26 is rotated forward as shown in FIG. 3, the control of the electric motor 17 and the operation and action of the jigsaw 10 Will be described in detail. FIG. 3A shows the rotational phase of the rotating member 26 when the plunger 42 is located at the top dead center. If the rotation angle of the rotation member 26 in FIG. 3A is “0 degree”, FIG. 3B shows a state in which the rotation member 26 is rotated 90 degrees clockwise from “0” degree. C) shows a state in which the rotating member 26 is rotated 180 degrees clockwise from “0” degrees. That is, the plunger 42 is located at the bottom dead center. FIG. 3D shows a state in which the rotating member 26 is rotated 270 degrees clockwise from “0” degrees.

  The connecting piece 41 is pressed against the rail 45B in the stroke in which the plunger 42 moves from the top dead center toward the bottom dead center. Further, the connecting piece 41 is pressed against the rail 45 </ b> A in a stroke in which the plunger 42 moves from the bottom dead center toward the top dead center. Therefore, when the rotating member 26 rotates clockwise as shown in FIG. 3, the reaction force received by the connecting piece 41 is transmitted to the plate 37 via the support shaft 39, and the plate 37 is pressed against the stopper 34 and stops. . Therefore, the radius r1 when the support shaft 39 revolves corresponds to the distance between the axis B1 and the center Q1 of the support shaft 39. The stroke amount L1 when the rotating member 26 rotates forward and the plunger 42 reciprocates in the direction of the center line C1 is twice the radius r1.

  Further, the operation of the operation control mechanism 58 will be described. When the switching lever 59 is at the operation position D1 as shown in FIG. 6, the notch 61 of the regulating shaft 60 is located near the swing arm 55 in the vertical direction of FIG. 2 as shown in FIG. Therefore, the swing arm 55 does not come into contact with the stopper 62, and the swing arm 55 can rotate clockwise and counterclockwise within a predetermined angle range around the support shaft 56. For example, as shown in FIG. 2, when the plunger 42 and the saw blade 43 are at the top dead center, that is, when the support shaft 39 is at the top dead center, the cam plate 51 is near the bottom dead center. In this case, the end of the cam plate 51 contacts the contact 54. For this reason, the plunger 42 and the saw blade 43 are in a state where the center line C1 is substantially vertical in FIG.

  As the support shaft 39 revolves, the cam plate 51 rises in synchronization with the movement of the plunger 42 and the saw blade 43 descending. When the cam plate 51 is raised, the swing arm 55 is rotated clockwise by a predetermined angle about the support shaft 56 by the force of the compression spring 50. For this reason, the operation trajectory of the lower end of the saw blade 43 is curved as the saw blade 43 descends from the top dead center toward the bottom dead center. That is, the saw blade 43 descends while leaving the object 11.

  On the other hand, in a stroke in which the plunger 42 and the saw blade 43 rise from the bottom dead center toward the top dead center, the cam plate 51 is lowered, and the swing arm 55 rotates a predetermined angle counterclockwise with the support shaft 56 as a fulcrum. Then, the saw blade 43 approaches the object 11 and is pressed against the object. Therefore, the saw blade 43 cuts the object 11 in the ascending process. The holder 47 rotates within a range of a predetermined angle about the support shaft 46 as the plunger 42 moves up and down. As described above, when the switching lever 59 is at the operation position D1, the rotating member 26 is normally rotated clockwise in FIG. 3 by the rotational force of the electric motor 17. Further, the operation trajectory of the saw blade 43 is controlled to be elliptical so that the saw blade 43 approaches the object in the ascending stroke and the saw blade 43 moves away from the object in the descending stroke. Thus, the fact that the swing arm 55 swings with the support shaft 56 as a fulcrum and the operation trajectory of the saw blade 43 is controlled to be elliptical is called “with orbital control”.

  Next, the operation and action of the jigsaw 10 when the switching lever 59 is at the operation position D2 as shown in FIG. 6B will be described. When the switching lever 59 is in the operation position D2, the tactile switch 68 is turned off, and the output shaft 20 of the electric motor 17 rotates in the first rotation direction. That is, when the switching lever 59 is at the operation position D2, the rotating member 26 rotates forward as shown in FIG. Therefore, when the switching lever 59 is at the operation position D2, the stroke amount when the saw blade 43 is raised and lowered is the same as the stroke amount of the saw blade 43 when the switching lever 59 is at the operation position D1.

  When the switching lever 59 is at the operation position D2, the stopper 62 and the notch 61 of the restriction shaft 60 are at the same position in the vertical direction. For this reason, the swing arm 55 is urged by the force of the compression spring 50 and always comes into contact with the stopper 62 and stops. That is, the swing arm 55 stops at the position rotated most counterclockwise about the support shaft 56 regardless of the operation of the cam plate 51. For this reason, the holder 47 does not swing around the support shaft 46 as a fulcrum in the stroke in which the plunger 42 and the saw blade 43 rise and fall. That is, when the switching lever 59 is at the operation position D2, the operation trajectory at the lower end of the saw blade 43 is linear. Thus, the fact that the swing arm 55 is stopped and the operation trajectory of the saw blade 43 is linear is referred to as no orbital control.

  Next, when the switching lever 59 is at the operation position D3 as shown in FIG. 6C, the control of the electric motor 17 and the operation and action of the jigsaw 10 will be specifically described. When the switching lever 59 is in the operation position D3, the tactile switch 68 is turned on, and the rotation direction of the output shaft 20 of the electric motor 17 is switched to the second direction. For this reason, the rotating member 26 rotates reversely as shown in FIG. FIG. 9A shows the rotational phase of the rotating member 26 in a state where the plunger 42 is located at the top dead center. If the rotation angle of the rotation member 26 in FIG. 9A is “0 degree”, FIG. 9B shows a state in which the rotation member 26 has rotated 90 degrees counterclockwise from “0” degree. 9 (C) shows a state in which the rotating member has rotated 180 degrees clockwise from “0” degrees. That is, the plunger 42 is located at the bottom dead center. FIG. 9D shows a state in which the rotating member has rotated 270 degrees counterclockwise from “0” degrees.

  The connecting piece 41 is pressed against the rail 45B in the stroke in which the plunger 42 moves from the top dead center toward the bottom dead center. Further, the connecting piece 41 is pressed against the rail 45 </ b> A in a stroke in which the plunger 42 moves from the bottom dead center toward the top dead center. Therefore, when the rotating member 26 rotates counterclockwise as shown in FIG. 9, the reaction force received by the connecting piece 41 is transmitted to the plate 37 via the support shaft 39, and the plate 37 is pressed against the stopper 35 and stopped. Is held in the state. Accordingly, the radius r2 when the support shaft 39 revolves corresponds to the distance between the axis B1 and the center Q1 of the support shaft 39. The radius r2 is shorter than the radius r1. Therefore, the stroke amount L2 when the rotating member 26 rotates in the reverse direction and the plunger 42 reciprocates in the direction of the center line C1 is twice the radius r2, and the stroke amount L2 is larger than the stroke amount L1. small.

  Further, the operation of the operation control mechanism 58 will be described. When the switching lever 59 is at the operation position D3 as shown in FIG. 6C, the stopper 62 of the regulating shaft 60 is at the closest position to the swing arm 55 in the vertical direction as shown in FIG. 10B. . For this reason, the swing arm 55 always contacts the stopper 62, and the swing arm 55 does not rotate around the support shaft 56. Therefore, when the switching lever 59 is at the operation position D3, the operation trajectory at the lower end of the saw blade 43 is linear.

  On the other hand, regardless of the position of the switching lever 59, the rotational force of the rotating member 26 is transmitted to the balance weight 30, and the balance weight 30 repeats the raising and lowering operations. The direction in which the balance weight 30 operates has a phase opposite to the direction in which the plunger 42 and the saw blade 43 operate. That is, when the plunger 42 and the saw blade 43 are raised, the balance weight 30 is lowered. On the other hand, when the plunger 42 and the saw blade 43 are lowered, the balance weight 30 is raised. For this reason, the inertial force due to the reciprocating motion of the plunger 42 and the saw blade 43 and the inertial force due to the reciprocating motion of the balance weight 30 are offset, and the vibration of the jigsaw 10 can be reduced.

  In the jigsaw 10 of the present embodiment, when the operation position of the switching lever 59 is switched, the rotation direction of the output shaft 20 of the electric motor 17 is switched, and the rotation direction of the rotating member 26 is switched between forward rotation and reverse rotation. . Further, when the rotation direction of the rotating member 26 is switched, the stroke amount of the reciprocating motion of the plunger 42 and the saw blade 43 changes. The support shaft 39, the plate 37, and the connecting piece 41 that convert the rotational force of the rotating member 26 into the reciprocating force of the plunger 42 also serve to change the stroke amount. The support shaft 39, the plate 37, and the connecting piece 41 correspond to the stroke amount changing mechanism 88 of the present invention. That is, it is not necessary to provide a dedicated mechanism for changing the stroke amounts of the plunger 42 and the saw blade 43 in accordance with the rotating direction of the rotating member 26. Therefore, it can suppress that the structure of the jigsaw 10 becomes complicated.

  Further, a recess 32 having a depth in the direction along the axis B <b> 1 of the rotating member 26 is provided, and the plate 37 is disposed in the recess 32. That is, the arrangement range of the rotating member 26 and the arrangement range of the plate 37 overlap in the direction along the axis B1. Therefore, the arrangement range or dimensions of the parts on the axis B1 can be suppressed, and the jigsaw 10 can be made compact.

  Another example of the stroke amount changing mechanism 88 is shown in FIGS. A guide hole 89 that penetrates the rotating member 26 in the direction of the axis B <b> 1 is provided, and the support shaft 39 is disposed in the guide hole 89. The support shaft 39 is movable in the longitudinal direction within the guide hole 89. The guide hole 89 includes inner end surfaces 90 and 91 at both ends in the longitudinal direction. Further, a stopper 92 that prevents the support shaft 39 from moving in the direction of the axis B <b> 1 with respect to the rotating member 26 is provided. The stopper 92 is fixed to the rotating member 26 and is rotatable about the support shaft 25. The support shaft 39 and the guide hole 89 constitute a stroke amount changing mechanism 88.

  When the switching lever 59 is at the operation position D1 or the operation position D2, the rotating member 26 rotates clockwise as shown in FIG. When the rotating member 26 rotates forward and the plunger 42 moves up and down, the connecting piece 41 is pressed against the rails 45A and 45B. The support shaft 39 is pressed against the inner end surface 91 by the reaction force of the pressing force and is positioned in the guide hole 89. Therefore, the radius r1 when the support shaft 39 revolves corresponds to the distance between the axis B1 and the center Q1 of the support shaft 39. Therefore, the stroke amount L1 when the rotating member 26 rotates forward and the plunger 42 reciprocates in the direction of the center line C1 is twice the radius r1.

  On the other hand, when the switching lever 59 is at the operation position D3, the rotating member 26 rotates counterclockwise as shown in FIG. When the rotating member 26 rotates forward and the plunger 42 moves up and down, the connecting piece 41 is pressed against the rails 45A and 45B. The support shaft 39 is pressed against the inner end surface 90 by the reaction force of the pressing force and is positioned in the guide hole 89. Accordingly, the radius r2 when the support shaft 39 revolves corresponds to the distance between the axis B1 and the center Q1 of the support shaft 39. The radius r2 is shorter than the radius r1. Further, the stroke amount L2 when the rotating member 26 rotates in the reverse direction and the plunger 42 reciprocates in the direction of the center line C1 is twice the radius r2, and the stroke amount L2 is shorter than the stroke amount L1. The jigsaw 10 provided with the stroke amount changing mechanism 88 of FIGS. 11 and 12 can obtain the same effects as described above.

  Next, an example of control executed by the motor control unit 80 of FIG. 8 will be described with reference to the flowchart of FIG. When the current is supplied from the AC power supply 75 and the motor control unit 80 is activated, the motor control unit 80 repeatedly executes the flowchart of FIG. 13 at predetermined time intervals. The motor control unit 80 determines whether or not the trigger switch 71 is turned on in step S1, and if the motor control unit 80 determines YES in step S1, whether or not the tactile switch 68 is turned on in step S2. Judging. If the motor controller 80 determines NO in step S2, the motor controller 80 controls the rotation direction of the electric motor 17 in step S3 to rotate the rotating member 26 in the forward direction.

  Further, the motor control unit 80 determines whether or not the trigger switch 71 is turned off in step S4, and if NO is determined in step S4, the control of step S3 is continued. If the motor control unit 80 determines YES in step S4, it stops the electric motor 17 in step S5 and ends the flowchart of FIG.

  If the motor control unit 80 determines YES in step S2, the motor control unit 80 controls the rotation direction of the electric motor 17 in step S6 to reversely rotate the rotating member 26. Further, the motor control unit 80 determines whether or not the trigger switch 71 is turned off in step S7, and if NO is determined in step S7, the control of step S6 is continued. If the motor control unit 80 determines YES in step S7, it stops the electric motor 17 in step S5 and ends the flowchart of FIG. If motor controller 80 determines NO in step S1, it repeats the determination in step S1.

  When the motor control unit 80 determines the rotation direction of the electric motor 17 in step S3 or step S6 when the flowchart of FIG. 13 was previously executed, the process proceeds to step S5 to stop the electric motor 17, and then the flowchart of FIG. Is executed this time and the process proceeds to step S2, and the rotation direction of the electric motor 17 is changed only when the determination result in step S2 is different between the previous time and the current time. That is, even if the tactile switch 68 is turned on and off while the electric motor 17 is rotating, the motor control unit 80 ignores the signal of the tactile switch 68 and does not change the rotation direction of the electric motor 17.

  Another example of the control system used for the jigsaw 10 will be described with reference to FIG. The switching lever 59 of the control system shown in FIG. 14 includes two operation positions D1 and D2, and does not include the operation position D3. The position in the rotational direction of the regulating shaft 60 at the operation positions D1, D2 of the switching lever 59 is as shown in FIG. 2 and FIG. That is, when the switching lever 59 stops at the operation position D1, the orbital control is performed, and when the switching lever 59 stops at the operation position D2, the orbital control is not performed. Further, an orbital switch 95 for detecting the operation positions D1 and D2 of the switching lever 59 is provided. The orbital switch 95 is turned on when the switching lever 59 stops at the operation position D1, and turned off when the switching lever 59 stops at the operation position D2. A signal output from the orbital switch 95 is input to the controller 81.

Further, a rotation direction switching lever 94 that switches the rotation direction of the electric motor 17 is provided. That is, the switching lever 59 and the rotation direction switching lever 94 are provided separately.
The rotation direction switching lever 94 is attached to a position visible from the outside of the housing 12, and the operator can operate the rotation direction switching lever 94. The tactile switch 68 detects an operation of the rotation direction switching lever 94, and a signal output from the tactile switch 68 is input to the controller 81. The motor control unit 80 controls the rotation direction of the electric motor 17 so that the rotating member 26 rotates forward when the tactile switch 68 is turned off. When the tactile switch 68 is turned on, the rotating member 26 rotates backward. Thus, the rotation direction of the electric motor 17 is controlled. As described above, in the control system shown in FIG. 14, the operation of the switching lever 59 and the operation of the rotation direction switching lever 94 can be performed independently.

  Next, a control example that can be executed by the motor control unit 80 shown in FIG. 14 will be described with reference to the flowchart of FIG. When a current is supplied from the AC power supply 75 and the motor control unit 80 is activated, the motor control unit 80 repeatedly executes the flowchart of FIG. 15 at predetermined time intervals. The motor control unit 80 determines whether or not the trigger switch 71 is turned on in step S11. If the motor control unit 80 determines YES in step S11, whether or not the orbital switch 95 is turned on in step S12. Judging. If it is determined YES in step S12, the motor control unit 80 controls the rotation direction of the electric motor 17 in step S13 to rotate the rotating member 26 in the normal direction.

  Further, the motor control unit 80 determines whether or not the trigger switch 71 is turned off in step S14, and returns NO to step S12 if NO is determined in step S14. If the motor control unit 80 determines YES in step S14, the motor control unit 80 stops the electric motor 17 in step S15 and ends the flowchart of FIG.

  If the motor control unit 80 determines NO in step S12, it determines whether or not the tactile switch 68 is turned on in step S16. If it is determined YES in step S16, the motor control unit 80 controls the rotation direction of the electric motor 17 in step S17 to rotate the rotating member 26 in the reverse direction. Further, the motor control unit 80 determines whether or not the trigger switch 71 is turned off in step S18, and returns NO to step S12 if NO is determined in step S18.

  If the motor control unit 80 determines YES in step S18, it stops the electric motor 17 in step S15 and ends the flowchart of FIG. If motor controller 80 determines NO in step S16, it executes the process of step S13.

  As described above, when the orbital control is performed, the motor control unit 80 controls the rotation direction of the electric motor 17 to rotate the rotating member 26 forward regardless of whether the tactile switch 68 is on or off. Further, the motor control unit 80 permits the rotating member 26 to reversely rotate only when there is no orbital control and the tactile switch 68 is turned on. That is, the motor control unit 80 prohibits the reverse rotation of the rotating member 26 when orbital control is present. In other words, when the orbital control is present, the motor control unit 80 does not switch the rotation direction of the electric motor 17 even when the tactile switch 68 is switched from OFF to ON.

  Here, the correspondence between the configuration of the present embodiment and the configuration of the present invention will be described. The rotating member 26 corresponds to the rotating member of the present invention, and the plunger 42 corresponds to the tool support member of the present invention. The direction along the center line C1 corresponds to the first direction of the present invention. The second direction of the present invention is a direction that intersects the center line C1 in a plane parallel to both the axis B1 and the center line C1. The motion conversion mechanism 96 corresponds to the motion conversion mechanism of the present invention, and the jigsaw 10 corresponds to the reciprocating operation machine of the present invention. The first operation of the present invention is that the plunger 42 moves in the direction along the center line C1 with respect to the holder 47 without orbital control, that is, without the holder 47 swinging around the support shaft 46 as a fulcrum. Corresponds to the state. Further, the state with orbital control, that is, the holder 47 swings around the support shaft 46 as a fulcrum, and the plunger 42 moves in the direction along the center line C1 with respect to the holder 47. This corresponds to two operating states.

  The operation control mechanism 58 corresponds to the operation control mechanism of the present invention, the electric motor 17, the inverter circuit 74, and the motor control unit 80 correspond to the rotation direction switching mechanism of the present invention, and the stroke amount changing mechanism 88 is This corresponds to the stroke amount changing mechanism of the present invention, the axis B1 corresponds to the rotation center and the axis of the present invention, the support shaft 39 and the connecting piece 41 correspond to the revolution member of the present invention, and the contact member 44 corresponds to the present invention. It corresponds to the contact member of the invention. The support shaft 36 corresponds to the support shaft of the present invention, the plate 37 corresponds to the operating member of the present invention, the recess 32 corresponds to the recess of the present invention, and the electric motor 17 corresponds to the motor of the present invention. The coils U1, V1, and W1 correspond to the coil of the present invention, the output shaft 20 corresponds to the output shaft of the present invention, and the motor control unit 80 corresponds to the control unit of the present invention. The switching lever 59 shown corresponds to a “single operation unit” in the present invention. The operation position D2 corresponds to the first operation position of the present invention, the operation position D1 corresponds to the second operation position of the present invention, and the operation position D3 corresponds to the third operation position of the present invention.

  Further, the rotation direction switching lever 94 shown in FIG. 14 corresponds to the first operation unit of the present invention, and the switching lever 59 shown in FIG. 14 corresponds to the second operation unit of the present invention, and the orbital switch 95 and the motor control. The unit 80 corresponds to the state detection unit of the present invention, and the stroke amount L1 corresponds to the predetermined amount of the present invention. Further, the position of the revolving member in the radial direction of the rotating member is determined by the radii r1 and r2.

  The reciprocating machine according to the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, a motor that generates power to be transmitted to a work tool includes an engine, a hydraulic motor, and a pneumatic motor in addition to an electric motor. By providing a rotation direction switching mechanism, which is a well-known technology, in the power transmission path between the output shaft and the rotating member, the rotation direction of the output shaft of the motor is the same, and the rotating direction of the rotating member is reverse to the normal rotation. It may be possible to switch between. The electric motor may be either a brushless motor or a brush motor.

  In the reciprocating machine according to the present invention, the electric power of the battery pack attached to the housing is supplied to the electric motor in addition to the reciprocating machine in which the power of the commercial power source is supplied to the electric motor via the power cord. Includes reciprocating machines. The battery pack is obtained by housing battery cells in a housing case, and the battery pack is detachable from the housing. That is, when an electric motor is used as the motor, the power source may be either a DC power source or an AC power source. Further, the rotating member includes a gear, a carrier of the planetary gear mechanism, a pulley, a rotating shaft, and a flange provided on the rotating shaft. That is, the rotating member may be an element that transmits the rotational force of the motor to the motion conversion mechanism.

  In addition, a push button or a knob can be used as the operation member operated by the operator to switch the rotation direction of the rotation member, instead of the switching lever and the rotation direction switching lever. A push button structure or a knob can be used as the operation member operated by the operator to switch between the presence and absence of the orbital control, instead of the switching lever of the rotation structure. Furthermore, it is also possible to use a known crank mechanism as a motion conversion mechanism without using a revolving member. The crank mechanism has a structure in which a rotating member is a crankshaft and a tool support member is connected to the crankshaft via a connecting rod.

  DESCRIPTION OF SYMBOLS 10 ... Jigsaw, 17 ... Electric motor, 20 ... Output shaft, 32 ... Recessed part, 36, 39 ... Support shaft, 37 ... Plate, 41 ... Connecting piece, 44 ... Contact member, 58 ... Operation control mechanism, 59 ... Switching lever, 74: inverter circuit, 80: motor control unit, 88: stroke amount changing mechanism, 94: rotation direction switching lever, 95: orbital switch, B1: axis, U1, V1, W1 ... coil, D1, D2, D3 ... operation position .

Claims (12)

A reciprocating machine with a motion conversion mechanism for reciprocating the tool support member in the first direction by the rotational force of the rotating member,
A first operation state in which the tool support member is operated only in the first direction; and a second operation state in which the tool support member is operated in a second direction intersecting the first direction in addition to the first direction. An operation control mechanism for switching,
A rotation direction switching mechanism that switches the rotation direction of the rotating member between forward rotation and reverse rotation;
A stroke amount changing mechanism that makes the stroke amount that the tool support member reciprocates differ between when the rotating member rotates forward and when it rotates backward;
A reciprocating machine. The motion conversion mechanism is
A revolving member provided on the rotating member and revolving around the rotation center of the rotating member;
A contact member that is provided on the tool support member so as to contact the revolution member, and that converts a revolution force of the revolution member into an operating force of the tool support member;
With
The stroke amount changing mechanism is configured to change the position of the revolving member in the radial direction of the rotating member so that the tool support member reciprocates depending on whether the rotating member rotates forward or backward. The reciprocating machine according to claim 1, wherein The stroke amount changing mechanism is
A support shaft provided at a position eccentric from the rotation center of the rotating member;
An operation member provided so as to be operable with the support shaft as a fulcrum, and having the revolution member attached thereto
With
The position at which the operation member operates and stops with the support shaft as a fulcrum differs depending on whether the rotation member rotates forward or reverse.
The reciprocating motion machine according to claim 2, wherein the position of the revolving member in the radial direction of the rotating member is changed when the operating member operates with the support shaft as a fulcrum. The rotating member includes a recess in a direction along an axis passing through the rotation center,
The reciprocating motion machine according to claim 3, wherein the operating member is disposed in the recess.   The reciprocating motion machine according to claim 4, wherein the operation member comes into contact with an inner peripheral surface of the recess and stops.   The reciprocating operation machine according to claim 1, wherein the rotation direction switching mechanism includes a motor capable of switching a rotation direction of an output shaft that transmits a rotation force to the rotation member. The motor is a brushless electric motor in which a current is supplied to a coil and the output shaft generates a rotational force,
The reciprocating motion machine according to claim 6, wherein the rotation direction switching mechanism includes a control unit that switches a rotation direction of the output shaft by switching a direction of a current supplied to the coil. A single operation unit operated by an operator is provided,
When the operation unit is operated, the control unit switches the rotation direction of the output shaft, and the operation control mechanism changes the operation of the tool support member between the first operation state and the second operation state. The reciprocating operation machine according to claim 7, wherein The operation unit is
A first operation position in which the operation state of the tool support member is the first operation state, and the output shaft is rotated forward to make the stroke amount of the tool support member a predetermined amount;
A second operation position in which the operation state of the tool support member is the second operation state, and the output shaft is rotated forward to set the stroke amount of the tool support member to a predetermined amount;
A third operation position in which the operation state of the tool support member is the first operation state, and the output shaft is reversely rotated to make the stroke amount of the tool support member smaller than a predetermined amount;
The reciprocating machine according to claim 8, comprising:   The reciprocating operation machine according to any one of claims 7 to 9, wherein the control unit prohibits switching of a rotation direction of the rotating member during rotation of the rotating member. The first operation unit and the second operation unit operated by the operator are provided separately,
The control unit switches a rotation direction of the output shaft when the first operation unit is operated,
The reciprocating operation machine according to claim 7, wherein the operation control mechanism switches an operation state of the tool support member when the second operation unit is operated. A state detection unit that detects an operation state of the tool support member during rotation of the rotation member is provided,
The control unit permits the reverse rotation of the rotating member by operating the first operation unit when the operation state of the tool support member is the first operation state, and the operation state of the tool support member The reciprocating operation machine according to claim 11, wherein when the motor is in the second operation state, it is prohibited to operate the first operation unit to reversely rotate the rotating member.

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